1. Field of the Invention
The present invention relates in general to a key structure and in particular to a key structure easy for assembly and disassembly, preventing separation of the key cover.
2. Description of the Related Art
Referring to FIG. 1, the conventional scissors type key structure primarily comprises a substrate 11, a first rod 12, a second rod 13, a resilient member 14 and a key cover 15. The first rod 12 has a first protrusion 16 and a second protrusion 17. The second rod 13 has a third protrusion 18 and a fourth protrusion 19. The first protrusion 16 rotatably connects the first receiving seat 20 of the key cover 15, and the second protrusion 17 rotatably and slideably connects the first convex trough 21 of the substrate 11 respectively. Moreover, the third and fourth protrusions 18, 19 rotatably connect the second convex trough 22 of the key cover 15 and the second receiving seat 23 of the substrate 11 respectively. With respect to the conventional scissors type key structure as shown in FIG. 1, the key cover 15 moves downward when the key is pressed. Subsequently, the key cover 15 can be raised upward due to the elastic force from the resilient member 14 disposed between the substrate 11 and the key cover 15.
To avoid separation of the key cover 15 from the first rod 12 after assembly, as shown in FIG. 2, the first receiving seat 20 defines a receiving space 25 and an opening 24 aligned to the center C thereof, wherein the width a of the opening 24 is less than the diameter b of the receiving space 25, and the diameter d of the first protrusion 16 is less or equal to the diameter b of the receiving space 25. When assembling the conventional key structure 1, the first protrusion 16 is inserted through the opening 24 into the receiving space 25 to securely connect the key cover 15, thus preventing separation.
As mentioned, the first protrusion 16 is securely joined in the receiving space 25 due to the width of opening 24 being less than the diameter of first protrusion 16. This method of assembly, however, is difficult and inconvenient. Furthermore, the key structure may be damaged when the first protrusion 16 is inserted through the small opening 24.